Product settling means for draw type wrapping machine



Dec. 8, 1959 J. s. BARTLO 2,915,866

PRODUCT SETTLING MEANS FOR DRAW TYPE WRAPPING MACHINE Filed May 12. 1958 lNVENTOR ATTORNEYS.

United States Patent PRODUCT SETTLING MEANS FOR DRAW TYPE WRAPPING MACHINE John S. Bartlo, Oakland, N.J., assignor to Lynch Corporation, a corporation of Indiana Application May 12, 1958, Serial No. 734,592 7 Claims. (Cl. 53-124) This invention relates generally to improvements in 'draw type wrapping machines, and more particularly to :a novel mechanism for effecting the settling and compacting of bulky, lightweight materials below the sealing jaws of a draw type wrapping machine during final package forming.

Draw type wrapping machines of the type which are operative to automatically form pillow-type packages for bulk materials and for individual and multiple articles are in increasingly widespread and favorable use. Although such machines as have been known in the past are efliciently adaptable to the performance of packaging operations on a wide variety of materials, the wrapping of bulky and lightweight products such as potato chips, corn curls, cheese puffs, and the like has been severely handicapped by the wide variation in density of such products and by their characteristic fragility and reluctance to settle during the bag-forming operation. When these product variations and weight characteristics are compensated for by making the bag of suflicient length to accept the greatest volume which the product may assume, the resulting packages are poorly filled and the subsequent settling of the product during shipping and retail handling renders the appearance of the package highly undesirable. Although the consumer may receive a package having the proper net weight of product, it will have the appearance of having been only partially filled, and the adverse effect upon the sales appeal of such a package normally precludes the use of fully automatic draw type wrapping machines for the packaging of such pr0ducts.

In the copending application, Serial No. 694,399, filed November 4, 1957, of which I am a co-inventor, there is disclosed a recent and improved form of draw type wrapping machine typical of the kind of machine for which the present invention is intended as an improvement, to enable automatic operation with bulky and lightweight products while achieving a package having an acceptably full appearance. Such machines comprise a supply of packaging material in web form, a tube former and edge sealing means operative to form the web into a continuous hollow tube, a sealing jaw carriage, a pair of sealing dies .carried by the carriage and movable to closed engagement with the tube, and drive means for reciprocating the sealing jaw carriage through a tubedrawing stroke and for alternately closing and opening.

the dies to effect the formation of a consecutive series of filled and sealed pillow-type packages.

It is the primary object of this invention to provide an improvement in draw type wrapping machines comprising, in combination with the sealing dies of such machines, a novel and fully automatic product settling means operative to insure proper product compacting and bag fill, while maintaining aclearance of the product with the die faces, during packaging operations performed with bulky .and lightweight products.

2,915,866 Patented Dec. 8, 1959 ice It is another object of this invention to provide a product settling mechanism adapted to be mounted upon a pair of opposed package sealing dies, comprising a pair of rods, one on each opposed die, supported by pivoted levers operative to move the rods toward engagement with each other as the dies are closed, and, in response to the resistance of the packaging material, elfect a downward pivoting movement of the rods toward a final position entirely below the dies and in close adjacency with each other so as to effect a downward compacting of the product being packaged and a clearance thereof with the die faces.

Further objects and advantages of this invention will become apparent as the following description proceeds, and the features of novelty which characterize this invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

A preferred embodiment of the invention is shown in the accompanying drawing, in which:

Figure 1 is a perspective view of a single die of a draw type wrapping machine, and having a settling rod assembly constructed in accordance with the principles and features of the present invention mounted thereon.

Figures 2, 3 and 4 are fragmentary side elevational views illustrating the operative movement of a pair of opposed dies of the type shown in Figure l as a package sealing operation is performed, and illustrating the manner in which the settling rod assemblies of the present invention insure a compacting of the product being packaged and its clearance from obstruction at the zone of sealing between the die faces.

Referring now to the drawing, I have indicated generally at It) a settling rod assembly embodying the present invention. A pair of sealing dies 12 and 14 of the type adapted to be moved in a reciprocatory cycle through a tube drawing stroke and also adapted to be moved toward and away from each other for alternately sealing and releasing a package therebetween, in the well known manner of draw type wrapping machines, are each provided with a settling rod assembly 10 for opposed coaction during package sealing. The dies 12 and 14each provide sealing faces 16 and 18 which are operative when brought into contacting engagement to effect sealing closure of a tube of suitable packaging material. A forming and filling tube 20 is operative in conventional manner to provide a continuous hollow tube of packaging material and to deliver thereinto a predetermined charge of a product P to be packaged. The bottom edge seal of the package being formed is indicated at 24, and marks the line of severance of a completed package previously formed immediately therebelow. It is contemplated that the product P is a bulky and low-density or lightweight material which does not normally effect a proper self-settling by gravity forces alone.

As best seen in Figure 1, the settling rod assembly 10 comprises an elongated mounting bracket 26 extending substantially the full length of the sealing die 12 and fixedly secured thereto by means of bolts 28 and 29. A

. pair of upstanding support arms 3i) and 32 are provided at the opposite ends of the brackets 26 and serve to support a pair of bearing blocks 34 and 36 in generally horizontal and rearwardly extending relation therefrom overlying the top surface of the sealing die 12. A pivot rod 38 is rotatably supported at its ends by the blocks 34 and 36. A pair of levers 40 and 42 are each secured at their fixed end by a pivot 44 to the respective bearing blocks 34 and 36. The free ends of the levers 40 and 42 serve to rotatably support a settling roller cr rod, indicated at 46A in connection with die 12 and at 468 in connection with die 14. The rods MA-and 46B of the respective settling rod assemblies are preferably formed of a firm but low coefiicient of friction of material such as nylon a s or similar thermoplastic resinous material. Roller pins 48 serve to secure the opposite ends of the settling'roller rods to the levers 40 and 42 in a freely rotatable manner.

-A stop plate 50 is mounted atopone of the bearing blocks 3.4, and-extends in overhanging relation outwardly over the adjacent lever .40. An adjustable stop screw 52 extendsdownwardly through the plate 50 for cooperative engagement with a fiat surface 54 of the lever 40. In this way, the position of the settling rod 46A forwardly of and at the same height level as the die face 16 may be adjustably predetermined by rotation of the stop screw 52. A pair of anchor screws 56 and 58 serve to mount the ends of a tension spring 60 for biasing the settling rod 46Ain its uppermost position with the stop screw 52 inlimiting engagement against the lever flat surface 54.

Referring now more particularly to the sequence, of Figures 2 through 40f the drawing, the practical operation. of the present invention will be summarized. In Figure 2, the hollow tube of'packaging material 22 has just received the charge of product P to be packaged.

The dies 12 and 14 are actuated for closing movement toward each other to effect a sealing of the tube 22 between the die faces 16 and 18.. It will be apparent that at this stage the uppermost particles of the product P lie directly in the path of the die faces and may be expected to prevent sealing closure of the package and .perhaps risk a jamming of the machine. Normally, this hazard has been prevented in the past by selecting an excessive bag length. The tube height below the level .of the sealing dies 12 and 14.0f Figure 2 represents the desired bag length for an attractive and substantially full package.

As the sealing dies 12 and 14 approach each other in Figure 3, the settling rods 46A and 46B are brought into engagement against the packaging material tube 22, and the force of engagement will serve to overcome the biasing tension of the springs 60 of each assembly 10. Since the levers 4t) and 42 .of, each assembly are pivoted at a point 44 which is located above and to the rear of the settling rods, the levers will be pivoted downwardly and rearwardly as bag closing movement progresses. At the same time, the uppermost product particles will be forced downwardly within the bag being formed so as to effect a compacting and settling thereof below the level of the sealing dies 12 and 14.

When the dies have been moved into bag sealing engagement as seen in Figure 4, the settling rods 46A and 4613 will have been brought into substantially contacting engagement with each other and with the flattened tube of packaging material closed therebetween. The settling rods 46A and 46B will then be located entirely below the sealing dies 12 and 14, with the pairs of supporting levers 40 and 42 lying alongside the opposite ends of the respective sealing dies. As thesealing dies separate and are moved apart to release the completely formed and filled bag B therebelow, the springs 60 will return the settling rollers 46A and 46B to their initial positions, as seen in Figure 2, preparatory to the next bag sealing cycle of movements.

The product settling means of the present invention may be applied to wrapping machines of the so-called double draw type, wherein separate pairs of sealing jaws are cyclically reciprocated so that a first closed pair of jaws effects a drawing operation while moving downwardly between a second open pair of jaws, which have just completed a drawing operation and are moving upward-1y to effect the next jaw-closing and drawing action. A machine of this type is disclosed in the aforesaid copending application Serial No. 694,399 In machines of the double draw type, it is important to insure withdrawal of the settling rods 46A and 463 to their positions below the respective sealing dies 12 and 14 (as seen in Figure 4 of the drawing) when the open pair of sealing jaws are moving upwardly about the downwardly-moving closed pair of jaws. If this precaution is not taken, the settling rods 46A and 46B of the upwardly mpving pair of sealing jaws will be 'in the path of the downwardl moving closed jaws, and will be engaged and forcibly pivoted toward their withdrawn position. It will be apparent that the repeated engagement between the various moving parts will result in undesirable wear and noise in the machine. It will also be apparent that even in machines of the single draw-type, full extension of the settling rods, as the sealing jaws eifect an upward or return stroke, may cause an;upward wiping of the product in the lower portion of the next bag to be formed and thereby p nt l n proper fil in i e c m y be particularly adverse When highly pliable packaging films, such as polyethylene, are employed. 7

I have indicated in Figure 1, therefore, a cam block '62 fixedly secured to the pivot rod 38, it is contemplated that a cooperating and mating cam member will be carried by a suitable fixed frame portion of the packaging machine, or by the carriage of the other of the two pairs of sealing jaws in the case of ,a double draw type machine, n such a o perat n c n; member Will r fl n e: m n wit the can; 62 as the la is a i pw d y its reciprocatory cycle to perform its next closing and 7 ra troke- 4 wrapping machine the improvement of product settling means, said product settling means comprising a contact member carried by said sealing die and normally dis,- posed in spaced relation forwardly and at the level of the sealingface of said s'ealing'die, said contact member being pivotally secured to said sealing die for down: ward and rearward movement to a position entirely therebelow in response to the engagement force of said contact member with a tube of packaging material to be sealed by said sealing die; a

2. In combination with a pair of sealing dies of a draw type wrapping machine the improvement of product settling means, said product settling means comprising a pair of rods each carried by one of said sealingdies and normally disposed in spaced opposed relation therebetween at the level thereof, said rods each being pivotally secured to a respective sealing die for downward and rearward movement to a position of immediately adjacent opposed relation entirely therebelow in response,

' to the engagement force of said rods with a tube of packaging material to be sealed as said dies are moved into closed relation, for progressively closing the'upper end of a package to be formed and for compacting a product therein while enabling unobstructed closure of said sealing dies.

3. In combination with a pair of sealing dies of a draw type wrapping machine the improvement of product settling means, said product settling means comprising a pair of rods each carried by one of said sealing dies, biasing and limit means normally disposing said sealing'dies in spaced opposed relation therebetween at the level thereof, said rods each being pivotally secured to a respective sealing die for downward and rearward movement to a position of immediately adjacent opposed relation entirely therebelow in response to the engagement force of said rods with a tube ofpackagiug material to be sealed as said dies are moved into closed relation, for progressively closing the upper end of a package to be formed and for compacting a product therein while enabling unobstruoted closure of said selaing dies.

4. In combination with a pair of sealing dies of a draw type wrapping machine the improvement of product settling means, said produgt settlingmeans comprising a pair of elongated rollers each carried by one of said sealing dies and normally disposed in spacedopposed parallel relation intermediate said dies and at the level thereof, said rollers each being freely rotatable and pivotally secured to a respective sealing die for downward and rearward movement to a position of immediately adjacent opposed relation entirely therebelow in response to the rolling engagement force of said rollers with a tube of packaging material to be sealed as said dies are moved into closed relation, for progressively closing the upper end of a. package to be formed and for compacting a product therein while enabling unobstructed closure of said sealing dies.

5. In a draw type wrapping machine of the kind having means operative to form a continuous hollow tube of packaging material, a pair of sealing dies having contact faces movable to closed engagement with said tube, and drive means to reciprocate said sealing jaw carriage through a tube-drawing stroke and to alternately close and open said dies, the improvement in combination with said sealing dies of product settling means, said product settling means comprising a pair of rods each carried by one of said sealing dies and disposed in normally spaced opposed relation intermediate said die faces, said rods each being pivotally secured to a respective sealing die for downward and rearward movement to a position of immediately adjacent opposed relation entirely therebelow in response to the engagement force of said rods with said tube as said dies are moved into closed relation, whereby to progressively close the upper end of the package being formed and compact a product therein while enabling unobstructed closure of said die faces against said tube.

6. In a draw type wrapping machine of the kind having means operative to form a continuous hollow tube of packaging material, a pair of sealing dies having contact faces movable to closed engagement with said tube, and drive means to reciprocate said sealing jaw carriage through a tube-drawing stroke and to alternately close and open said dies, the improvement in combination with said sealing dies of product settling means, said product settling means comprising a pair of elongated rollers each carried by one of said sealing dies and normally disposed in spaced opposed parallel relation intermediate said die faces and at the level thereof, said rollers each being freely rotatable and pivotally secured to a respective sealing die for downward and rearward movement to a position of immediately adjacent opposed relation entirely therebelow in response to the rolling engagement force of said rollers with said tube as said dies are moved into closed relation, whereby to progressively close the upper end of the package being formed and compact a product therein while enabling unobstructed closure of said die faces against said tube.

7. In combination with a sealing die of a draw type wrapping machine the improvement of product settling means, said product settling means comprising a contact member carried by said sealing die and normally disposed in spaced relation forwardly and at the level of the sealing face of said sealing die, said contact member being pivotally secured to said sealing die for downward and rearward movement to a position entirely therebelow in response to the engagement force of said contact member with a tube of packaging material to be sealed by said sealing die, and cam means operatively connected to said contact member and adapted to engage a cooperating cam member during the upward return stroke of a drawing cycle, said cam means serving when engaged to effect pivotal downward and rearward movement of said contact member to its position entirely below said sealing die.

References Cited in the file of this patent UNITED STATES PATENTS 1,353,210 Bates Sept. 21, 1920 2,576,471 Messmer et a1 Nov. 27, 1951 2,828,591 Bossche Apr. 1, 1958 

